Re: Is *fast* 32-bit support still important?

On 29/07/2024 23:40, Joel Jacobson wrote:
> To me, it's non-obvious whether introducing `#if SIZEOF_DATUM < 8` with
> separate 32-bit and 64-bit code paths is worthwhile to maintain performance
> for both.
> 
> Knowing more about $subject can hopefully help us reason about how much
> additional code complication is justifiable for *fast* 32-bit support.

IMO I don't think it's worth adding extra code for fast 32-bit support 
anymore. However, I'd still be wary of *regressing* performance on 
32-bit systems.

So if you're adding a new fast path to a function, it's OK to make it 
64-bit only, and fall back to the old slower code on 32-bit systems. But 
-1 on *removing* existing 32-bit fast path code, or rewriting things in 
a way that makes an existing function significantly slower than before 
on 32-bit systems.

This isn't black or white though. It depends on how big a gain or 
regression we're talking about, and how complex the extra code would be.

-- 
Heikki Linnakangas
Neon (https://neon.tech)